Monitor Description

These DTCs are designed to detect a malfunction in the air pump heater relay (AIR PUMP HTR) circuit. When the system is normal, the battery voltage is applied to terminal HAI1 of the ECM while the air pump heater relay (AIR PUMP HTR) is turned off, and the battery voltage is not applied to terminal HAI1 of the ECM while the air pump heater relay (AIR PUMP HTR) is turned on. The ECM illuminates the MIL and stores a DTC when either one of the following conditions is detected.

• The battery voltage is not applied to terminal HAI1 while the air pump heater relay (AIR PUMP HTR) is off.
• The battery voltage is applied to terminal HAI1 while the air pump heater relay (AIR PUMP HTR) is on.